Occurrence of the Ponto-Caspian mysid shrimp Hemimysis anomala (Crustacea, Mysida) in the St. Lawrence River

Åsa Kestrup

doi:10.3391/ai.2008.3.4.17

Abstract

An invasive Ponto-Caspian shrimp, the bloody-red mysid Hemimysis anomala, is recorded for the first time in the St. Lawrence River near Montreal. The presence of gravid females and juveniles suggest an ongoing colonization of the river, likely driven by downstream dispersal of individuals from source populations in Lake Ontario. Two years after being discovered in Lake Michigan and Lake Ontario, H. anomala has now been recorded in all major waterbodies within the Great Lakes-St. Lawrence system, except for Lake Superior.

Highlights

Since the 1980s, the North American Great Lakes have experienced a wave of invasions by animals originating from the freshwater and estuarine margins of the Black, Caspian and Azov Seas – the Ponto-Caspian region (Ricciardi and MacIsaac 2000)
These invaders include over a dozen species of protists, mussels, crustaceans and fishes, all likely introduced through ballast water release from transoceanic ships (Ricciardi 2006)
The North American invasion of H. anomala was predicted on the basis of its expansion throughout western Europe and the likelihood that the species would survive transport in ship ballast tanks (Ricciardi and Rasmussen 1998)

Summary

Introduction

Since the 1980s, the North American Great Lakes have experienced a wave of invasions by animals originating from the freshwater and estuarine margins of the Black, Caspian and Azov Seas – the Ponto-Caspian region (Ricciardi and MacIsaac 2000). The North American invasion of H. anomala was predicted on the basis of its expansion throughout western Europe (from whence the Great Lakes receives the bulk of its overseas shipping traffic) and the likelihood that the species would survive transport in ship ballast tanks (Ricciardi and Rasmussen 1998).

Results

Conclusion